Effect of Methane Flow Rate on Growth and Properties of TiSi-C:H Films Deposited by Middle-frequency Magnetron Sputtering

The TiSi-C:H films were deposited on the silicon and the stainless steel substrates by middle-frequency magnetron sputtering Ti80Si20 targets using the methane gas as the precursor. The effects of the methane flow rate on the deposition rate, the structure, the mechanical and tribological properties were investigated. The results demonstrate that the structure, the mechanical and tribological properties of the films strongly depend on the methane flow rate. The deposited films exhibit a transition from a tapered columnar nanocomposite structure consisting of ~10 nm nanocrystallites and amorphous phases to an amorphous structure with increasing of methane flow rate. The films deposited at a low methane flow rate show high hardness, high internal stress and high wear rates, whereas the films deposited at high methane flow rate show a decrease in hardness and internal stress but an improvement in tribological performance. The variations on the mechanical and tribological properties may be attributed to the evolution of the microstructures of the films with increasing of methane flow rate.